Fossil Insects from the Bemhridge Marls, Palaeogene of the Isle of Wight, Southern England
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Fossil insects from the Bemhridge Marls, Palaeogene of the Isle of Wight, southern England E. A. J arzembowski Department of Entomology, British Museum (Natural History), Cromwell Road, London SW7 SBD Contents Synopsis 238 Introduction 239 Previous studies 240 Notes on lithology, inclusions and method of study 240 Field sections . 242 Correlation 243 Systematic descriptions 244 Order Isoptera 244 Family Mastotermitidae 244 Genus Mastotermes Froggatt 244 Mastotermes anglicus von Rosen 245 Family Kalotermitidae 249 Genus Kalotermes Hagen 249 Kalotermes disruptus (Cockerell) 249 Family Rhinotermitidae 251 Genus Reticulitermes Holmgren 251 Reticulitermes sp. 251 Family Termitidae 253 Species A . 253 Family uncertain 253 Order Plecoptera . 253 Family Leuctridae 253 Genus Leuctra Stephens 253 Lellctra priscula (Cockerell) 253 Order Neuroptera 255 Family Mantispidae . 255 Genus Promantispa nov. 255 Promantispa relicta (Cockerell) 255 Family Hemerobiidae 257 Genus Hemerobius Linne 257 Hemerobius tinctus sp. nov. 257 Genus Nellronema McLachlan 259 ? NeurOflema sp. A 259 '! Nellronema sp. B 259 Genus indet. 260 Species A 260 Species B . 260 Species C . 260 Family Chrysopidae 260 Species A . 260 Family Sisyridae 261 Species A . 261 Family uncertain 262 Order Mecoptera . 262 Family Bittacidae 262 8ull. Br. lv/us. nat. Hist. (Geol.) 33 (4) : 237-293 Issued 27 March 1980 238 E. A. JARZEMBOWSKI Genus Bittacl/s Latreille . 262 Bittacils vetertillS (Cockerell) 262 Bitfacus sp. A 263 Order Lepidoptera 263 Family Micropterigidae 263 Genus Micropterix Hubner 263 ft,licropterix anglica sp. nov. 263 Family Hepialidae 265 Genus Prohepialus Piton 265 Prolrepialus sp. 265 Family Tineidae 267 Genus Paratriaxomasia nov. 267 Paratriaxomasia solentensis sp. nov. 267 Genus indet. 269 Species A . 269 SuperfamilY Gelechioidea 269 Species A . 269 Family Copromorphidae 270 Genus Copromorpha Meyrick 270 Copromorpha fossilis sp. nov. 270 Microlepidoptera, Family uncertain 270 Species A-L 270-275 ? Family Cossidae 275 Genus Gurtletia Cockerell 275 Glirnetia durranti Cockerell 275 Family Pyralidae 276 Genus pyralites Heer 276 Pyralites preecei sp. nov. 276 Family Geometridae . 278 Genus Geometridites Clark et al. 278 Geometridites larentiiformis sp. nov. 278 Family Nymphalidae 279 Genus Nymphalites Scudder 279 Nymphalites zellneri sp. nov. 279 Family Lycaenidae 282 Genus Lithopsyehe Butler 282 Lithopsyehe ant/qua Butler 283 ? Superfamily Papilionoidea 284 Genus indet. 284 Conclusions 284 Acknowledgements 286 References 286 Index 291 Synopsis The palaeontology, sedimentology and stratigraphy of the Insect Bed (Bembridge Marls) are discussed and previous work summarized. Five insect orders are revised, notes on the biology of living relatives are included and the palaeoecology considered. lsoptera: Mastotermes angliclls von Rosen is redescribed, Sisyra (?) disrupta Cockerell is transferred from the Nellroptera to Kalotermes s. lat. (Kalotermitidae); a species of Reticulitermes (Rhinotermitidae) and a termitid are described but not named. The Isoptera suggest a warm subtropical-tropical climate. Plecoptera: Nemoura priscufa Cockerell is transferred to the genus Leuctra (Lellctridae). Megaloptera: the record of Raphidia is shown to be erroneous. Neurop tera: Mantispidae: Mantispa reliefa Cockerell is transferred to Promantispa gen. nov. Hemerobiidae: Hemerobius tinclus sp. nov., ? Neuronema spp. A and B, and 3 unnamed species are described. Chry sopidae: a species of Chrysopinae (s. lat.) is described but not named. The affinities of an extinct sisyrid are discussed. Mecoptera: Panorpa vetertla Cockerell (Panorpidae) is transferred to the genus Blttacus (Bittacidae); an unnamed species of BiftacliS is described. Lepidoptera: lvlicropterix anglica sp. nov. PALAEOGENE INSECTS 239 (Micropterigidae), Paratriaxomasia solentensis gen. et sp. nov. (Tineidae), Copromorpha fossilis sp. nov. (Copromorphidae), Pyralites preecei sp. nov. (Pyralidae), Nymphalites zeuneri sp. nov. (Nymphalidae), Prohepialus sp. (HepiaJidae) and Ceometridites larentiiformis sp. nov. (Geometridae) are described. Lithopsyche antiqua Butler is transferred to the Lycaenidae and the placement of Curt/etia durranti Cockerell in the Cossidae is questioned. A tineid, a tentative gelechioid, 12 other species of microJepid optera and a possible papilionoid are described but not named. Introduction The Bembridge Marls are a predominantly argillaceous formation, 21~36 m thick, preserved only in the northerly half of the Isle of Wight in southern England (Fig. 1). Near the base of the formation is a thin clay bed, generally less than a metre thick, with concretions and tabular bands of fine-grained argillaceous limestone and hard marl. The latter, on the NW coast near Cowes, have been noted for their insect remains for just over a century and constitute the 'Insect Lime stone' of authors (Daley 1973a). However, the calcareous and argillaceous developments together 1 Hamstead Ledge / Cliff End ~ __~_~~5 Km Fig. 1 Outcrop map of the Bembridge Marls. form a distinct unit (ibid.) and the name Insect Bed (Bembridge Marls) used by Curry (1958) for a single limestone is here applied collectively. This horizon has yielded the only sizeable insect fauna in the British Tertiaries above the Lower Eocene, some fifteen orders being repre sented. The fauna also includes molluscs, an ostracod, an anostracous crustacean, an isopod, arachnids (spiders) and avian remains (feathers, Fig. 61, p. 268), the last three of which are scarce. Although named after the insects, the bed is probably better known in the palaeonto logical literature for its flora due to the work of Reid & Chandler (1926). However, apart from the leaves of a reed, well-preserved plant macrofossils are rare. Insect fragments are fairly frequent, and richer pockets are sometimes encountered (Jarzembowski 1976). The most extensive collections from this bed are now preserved in the British Museum (Natural History). These were largely collected by E. J. A'Court Smith (l814~1900), collecting between West Cowes and the Newtown River from about 1859 (Smith 1874). Apparently he discovered the insects following a comment by Forbes (1856 : 58~59) on the insect-bearing nature of some similar limestones in the Purbeck Beds (late Jurassic~early Cretaceous) on the mainland (Hughes 1922 : 67; Jackson 1933). Much of A'Court Smith's material subsequently went to R. W. Hooley and the Rev. P. B. Brodie, and the history of the collections and their acquisition by the Museum are given in Reid & Chandler (1926) and Crane & Getty (1975). Notable smaller collections from the Insect Bed include one at the Museum of Isle of Wight Geology, which was mainly the work of G. W. Colenutt, and another consisting of sonic of Brodie's material in the Lacoe Collection at the United States National Museum; I have myself collected from the bed since 1966. The fossil insect collections at the British Museum (Natural History) contain over 3900 pieces of 'Insect Limestone' of which a large proportion bear two or more specimens. However, a 240 E. A. JARZE,'vIBOWSKI number of these are indeterminate and some species, especially in the Formicidae, are repre sented by numerous examples. The present paper is confined to the Isoptera, Plecoptera, Neurop tera, Mecoptera and Lepidoptera, which although rare or uncommon have yielded a varied range of taxa; several other orders are being studied. AU available material is documented, and in addition to systematic and taxonomic considerations, the ecological and biological require ments of Recent relatives are briefly discussed. Previous studies A'Court Smith (I874) appears to be the first published record of the occurrence of arthropod remains in the Insect Bed near Cowes. Woodward (1878, 1879) published a list of identifications made by Frederick Smith of the Department of Zoology, British Museum (Natural History), based on a sample of A'Court Smith's collection. In the 1879 paper Woodward described an anostracan, Branchipodites vectcnsis, and an isopod, Eosphaeroma fluviatile, from the same horizon; Martini (1972) showed the latter to be a synonym of the continental species Eosphaeroma margarum (Desmarest 1822). McCook (1888a, b) gave two identical descriptions of a mygalo morph spider, Eoatypus woodwardii, and Jones & Sherborn (1889) described an ostracod Pota mocypris brodiei which Haskins (1968) compared with Cypridopsis, another freshwater genus. The first description of an insect, Lithopsyche antiqua Butler 1889, was accompanied by c. colour plate. This was followed by von Rosen (1913) on fossil M~astotermes, and in 1915, T. D. A. Cockerell described 33 new insect species from the Lacoe Collection. He subsequently made selective studies of the main collection at the BM(NH): Cockerell (1917a, 1921a, b, c, 1922); Cockerell & Andrews (1916); Cockerell & Haines (1921). The Formicidae were studied by Donisthorpe (1920), the Culicidae by Edwards (1923) and Orthoptera by Zeuner (1939). These constitute the main works on the insect fauna and, although the flora was monographed by Reid & Chandler (1926), there is no comprehensive work on the arthropods. Chandler (1964) reviewed the Bembridge Flora, including the microfloral work of Machin (nee Pallot) published later in 1971. Although the junction of the Bembridge Marls and Bembridge Limestone is unconformable (Daley & Edwards 1971), the palaeobotanists considered the Bembridge Beds to contain a single flora, and it is not always clear which taxa occur in the Insect Bed. Daley (1969) studied the